The present invention relates to capping devices for use with medical devices such as endotracheal tubes, endobronchial tubes and connectors therefore.
During continuous mechanical ventilation of patients, a common clinical practice involves the use of Positive End Expiratory Pressure, wherein the ventilator provides a specific amount of pressure during the expiratory phase of ventilation. This "pressure breathing" facilitates ventilating the entire lung system of the patient, and assists the breathing of those with injuries or debilitating illnesses having breathing difficulties. The slight positive pressure of the incoming air during gas assist inhalation must be overcome during expiration, and suitable valves and pressure regulators are placed in the ventilation circuit to allow for expiration.
It is often necessary to have access to a patient's airways during mechanical ventilation. For example, one procedure that is frequently performed is bronchoscopy. Bronchoscopy involves the insertion of a thin instrument, called a bronchoscope, into a patient's airways for visual inspection of the patient's lung and bronchial passages. If access is not provided for in the ventilation system, the patient must be disconnected from the ventilator prior to insertion of the bronchoscope. If access is provided, such access must be sealable when the access is not needed so that the ventilation of the patient may be properly maintained. Further, it is also desirable that even when performing a procedure such as bronchoscopy, that the ventilation system remains sealed around the inserted instrument so as to maintain the ventilation pressure to as high a degree as possible.
There are numerous capping devices with access ports for ventilation tubes and connectors known in the prior art as represented by the following. However, all of the known capping devices suffer from disadvantages as will be discussed below.
U.S. Pat. No. 4,416,273 to Grimes shows a cap valve assembly which has a cap that allows for the admission of a thin tubular instrument while keeping sealed the end of the connector through which the instrument is inserted. However, the Grimes cap suffers from the disadvantage that the only way to fully open the connector is to completely disconnect the cap from the connector, thereby risking loss of the cap.
U.S. Pat. No. 4,580,556 to Kondur discloses a plugged connector cap wherein both the plug and the cap are independently tied to the connector by cords. While the cap cord of Kondur permits removal of the cap from its connector opening without disconnecting the cap from the connector, the cord can not be easily removed from the connector if it is desired to completely disconnect the cap from the connector, such as to replace the cap.
U.S. Pat. No. 3,814,103 to Fettel et al describes a stopper having an integrally formed holding strap for engaging a connector. This construction also allows for removal of the stopper without total disconnection from the connector, however, total removal of the stopper and holding strap is difficult. Also, this device does not provide for maintenance of maximum ventilation pressure when the stopper is in an open position.
U.S. Pat. No. 3,707,972 to Vallari et al shows a plug for one arm of a two channel irrigation system connector. The plug is permanently attached to the arm by a tether strap.
U.S. Pat. No. 3,741,217 to Clarico also describes a plug for one side arm of an irrigation system connector. This plug includes a tether strap with an attachment ring which circles the connector when in use. This keeps the plug attached to the connector when the plug is not engaged in the side arm opening, but total removal from the connector is difficult.
U.S. Pat. No. 4,661,110 to Fortier et al discloses a connector fitting of medical tubes having various plug adaptions for closing coupling elements which may be attached to the medical tube. The connector fitting of Fortier et al is tethered to the medical tube by a coupling ring, which makes removal from the tube difficult.
As seen above, the devices known from the prior art all have disadvantages. Further, none of the prior art capping devices are specifically designed to allow insertion of instruments into a ventilation tube while maintaining the maximum ventilating pressure. In addition, it is desirable to overcome other disadvantages related to the loss of ventilation pressure, such as by inadvertent displacement of the plug portion of the capping device.
Accordingly, there remains a need in the art for improvements in capping devices for covering openings in conduit connectors.